Intercellular transmission of chronic ER stress:a new mechanism of metabolic diseases

Cell-cell communication plays a critical role in cell proliferation,dif-ferentiation,morphogenesis,functiogenesis,and tissue homoeostasis in multicellular organ...     

Inducible CD4+LAP+Foxp3- regulatory T cells suppress allergic inflammation

Regulatory T cells (Tregs) play a critical role in the maintenance of airway tolerance. We report that inhaled soluble Ag induces adaptive Foxp3(+) Tregs, as well as a regulatory population of CD4(+) T cells in the lungs and lung-draining lymph nodes that express latency-associated peptide (LAP) on their cell surface but do not express Foxp3. Blocking the cytokine IL-10 or TGF-β prevented the generation of LAP(+) Tregs and Foxp3(+) Tregs in vivo, and the LAP(+) Tregs could also be generated concomitantly with Foxp3(+) Tregs in vitro by culturing naive CD4(+) T cells with Ag and exogenous TGF-β. The LAP(+) Tregs strongly suppressed naive CD4(+) T cell proliferation, and transfer of sorted OVA-specific LAP(+) Tregs in vivo inhibited allergic eosinophilia and Th2 cytokine expression in the lung, either when present at the time of Th2 sensitization or when injected after Th2 cells were formed. Furthermore, inflammatory innate stimuli from house dust mite extract, nucleotide-binding oligomerization domain containing 2 ligand, and LPS, which are sufficient for blocking airway tolerance, strongly decreased the induction of LAP(+) Tregs. Taken together, we concluded that inducible Ag-specific LAP(+) Tregs can suppress asthmatic lung inflammation and constitute a mediator of airway tolerance together with Foxp3(+) Tregs.     

Fish Intake and Risk of Liver Cancer: A Meta-Analysis

Background

Increasing laboratory findings indicate that n-3 fatty acids, mainly derived from fish, inhibit cancer development and progression, but results from epidemiologic studies have been inconsistent and inconclusive.

Objective

To evaluate the association of fish intake with risk of liver cancer by conducting a meta-analysis.

Methods

Published case-control/cohort studies that evaluated the relationship between total fish intake and risk of liver cancer were found on PubMed and EMBASE. The pooled relative risks (RRs) with 95% confidence intervals (CIs) were obtained with the random-effects model.

Results

Five retrospective case-control studies and 5 prospective cohort studies were included in the final analysis, involving a total of 3 624 liver cancer cases. Comparing the highest with the lowest category of total fish intake, the pooled RRs of liver cancer were 0.79 (95% CI, 0.59-1.06) for case-control studies, 0.82 (95% CI, 0.70-0.96) for cohort studies and 0.82 (95% CI, 0.71-0.94) for all studies combined. The protective effects of total fish intake against liver cancer were confirmed by stratified and sensitivity analyses. In addition, an increase in fish intake of 1 serving/week was estimated to be significantly associated with 6% lower risk of liver cancer (RR = 0.94, 95% CI, 0.91-0.98).

Conclusions

Findings from this meta-analysis suggest that a higher fish intake is associated with reduced risk of liver cancer.     

Novel functional variants locus in PLCE1 and susceptibility to esophageal squamous cell carcinoma: Based on published genome-wide association studies in a central Chinese population

A novel functional single nucleotide polymorphism (SNP) rs2274223 located in the phospholipase C epsilon 1 (PLCE1) gene was found to be associated with the risk of esophageal squamous cell carcinoma (ESCC) by three large-scale genome-wide association studies (GWAS) in Chinese populations. In the present study, we validated this finding and also explored the risk of ESCC associated with other two unreported potentially functional SNPs (rs17417407 G > T and rs2274224 C > G) of PLCE1 in a population-based case–control study to investigate the association between these three potentially functional SNPs in PLCE1 and susceptibility to ESCC. A total of 381 ESCC cases and 420 controls matched by age and sex were recruited and successfully genotyped for three SNPs (rs17417407, rs2274223 and rs2274224) of the PLCE1 in a central Chinese population. SNP rs2274223 was independently associated with increased risk of ESCC (adjusted odds ratio [OR], 2.80; 95% confidence interval [95% CI], 1.45–5.39 for GG vs. AA), and SNP rs2274224 was found to be associated with decreased risk of ESCC (adjusted OR, 0.65; 95% CI, 0.46–0.91 for CG vs. CC). The combined effects of risk alleles for three SNPs (rs17417407T, rs2274223G and rs2274224G) were found to be associated with elevated risk of ESCC in a dose-dependent effect manner (P_trend = 0.005). The G_rs17417407A_rs2274223C_rs2274224 haplotype decreased the risk of ESCC (adjusted OR, 0.76; 95% CI, 0.62–0.93), meanwhile the G_rs17417407G_rs2274223C_rs2274224 and T_rs17417407G_rs2274223C_rs2274224 haplotypes could increase the risk of ESCC (adjusted OR, 1.75; 95% CI, 1.33–2.18 and OR, 2.51; 95% CI, 1.15–2.49). Gene–environment interaction analysis presented a best model consisted of four factors (rs2274223, rs2274224, family history, and smoking) with testing balance accuracy (TBA): 0.66 and cross validation consistency (CVC): 7/10, which could increase the esophageal cancer risk in the “high risk group” with 3.67-fold (OR: 3.67, 95% CI: 2.74–4.92), compared to the “low risk group”. Our results further confirmed that genetic variations in PLCE1 may contribute to ESCC risk associated with tobacco exposure in a central Chinese population. Further functional studies are needed to validate our results.     

Non-hydroxamate 5-phenylpyrimidine-2,4,6-trione derivatives as selective inhibitors of tumor necrosis factor-alpha converting enzyme

New inhibitors of tumor necrosis factor-alpha converting enzyme (TACE) were discovered with a pyrimidine-2,4,6-trione in place of the commonly used hydroxamic acid. These non-hydroxamate TACE inhibitors were developed by incorporating a 4-(2-methyl-4-quinolinylmethoxy)phenyl group, an optimized TACE selective P1' group. Several leads were identified with IC50 values around 100 nM in a porcine TACE assay and selective over MMP-1, -2, -9, -13, and aggrecanase.     

Generation and characterization of pluripotent stem cells from cloned bovine embryos

Bovine embryonic stem (ES) cell lines reported to date vary in morphology and marker expression (e.g., alkaline phosphatase [ALPL], stage-specific embryonic antigen 4 [SSEA4], and OCT4) that normally are associated with the undifferentiated, pluripotent state. These observations suggest that the proper experimental conditions for consistently producing bovine ES cells have not been identified. Here, we report three bovine ES cell lines, one from in vitro-fertilized and two from nuclear transfer embryos. These bovine ES cells grew in large, multicellular colonies resembling the mouse ES and embryonic germ (EG) cells and human EG cells. Throughout the culture period, most of the cells within the colonies stained positive for ALPL and the cell surface markers SSEA4 and OCT4. The staining patterns of nuclear transfer ES cells were identical to those of the blastocysts generated in vitro yet different from most previously reported bovine ES cell lines, which were either negative or not detected. After undifferentiated culture for more than 1 yr, these cells maintained the ability to differentiate into embryoid bodies and derivatives of all three EG layers, thus demonstrating their pluripotency. However, unlike the mouse and human ES cells, following treatment with trypsin, type IV collagenase, or protease E, our bovine ES cells failed to self-renew and became spontaneously differentiated. Presumably, this resulted from an interruption of the self-renewal pathway. In summary, we generated pluripotent bovine ES cells with morphology similar to those of established ES cells in humans and mice as well as marker-staining patterns identical to those of the bovine blastocysts.     

Detection of local polarity of alpha-lactalbumin by N-terminal specific labeling with a new tailor-made fluorescent probe

To detect the local polarity such as the N-terminal domain of a protein molecule, 3-(4-chloro-6-hydrazino-1,3,5-triazinylamino)-7-(dimethylamino)-2-methylphenazine has been designed and synthesized as a polarity-sensitive fluorescent probe by using an s-triazine ring as a backbone, neutral red and hydrazine as a polarity-sensitive fluorophore, and a labeling group, respectively. The fluorescence properties of the probe have been characterized. The probe has the following features: (1) stable in various solvents; (2) the long-wavelength emission of >550 nm that can avoid the interferences of the background fluorescence shorter than 500 nm from common biomacromolecules; and (3) the maximum emission wavelength (lambda(em)) sensitive to solvent polarity only but not to pH and temperature. The hydrazino group in such a probe reacts readily with an active carbonyl produced by transamination of a protein molecule, leading to N-terminal specific attachment of the fluorophore and thereby allowing the monitoring of local polarity. With this probe, the polarity of the N-terminal domain in both native and heat-denatured alpha-lactalbumin has been first determined, which corresponds to that with a dielectric constant of about 16, and the hydrophobic core near the N-terminus is found to be conservative for heating. The present strategy may provide a general method to study the local environmental changes of a protein molecule under different denaturation conditions.     

Immunodepletion of albumin for two-dimensional gel detection of new mouse acute-phase protein and other plasma proteins

Immunodepletion of albumin to improve the 2-D gel resolution of human plasma proteins has recently been described. With the importance of mouse models in many studies in which serum or plasma is often analyzed, we have adopted this approach to immunoprecipitate mouse albumin and evaluated its effectiveness for 2-D separation of mouse plasma proteins. Purified polyclonal antibodies against mouse albumin were effective depleting intact albumin as well as its numerous fragments from mouse plasma samples. Removal of albumin resulted in better resolution of mouse plasma proteins. Three proteins, alpha2-macroglobulin, coagulation factor XII, and hemopexin, that were previously either undetectable or poorly resolved, were identified from albumin-depleted 2-D gels by peptide mass fingerprinting. Albumin depletion also led to partial loss of several other proteins such as clusterin and gelsolin. This loss can be attributed to the interaction with albumin itself because the specificity of the antibody was demonstrated by Western blot. When applying this method to the 2-D separation of plasma from inflamed mouse induced by cutaneous burn injury with superimposed Pseudomonas aeruginosa infection, the upregulation of inter alpha-trypsin inhibitor heavy chain 4 (ITIH4) and hemopexin was unambiguously detected along with other mouse acute-phase proteins (APP), including haptoglobin and serum amyloid A. Based on the significant increase of ITIH4, we propose that this protein is a new member of mouse APP that are upregulated during the inflammatory response.